Tracing apparatus



w. D. MASON 1,929,846

TRAC ING APPARATUS Filed May 3, 1932 2 Sheets-Sheet l INVENTOR ATTO NEY Get. 10, 1933. w D MASON 1,929,846

TRACING APPARATUS Filed May 5, 1932 2 Sheets-Sheet 2 INVENTOR VKDMasom Patented Oct. 10, 1933 i'nicme Armenia.

'Williani Mason, lfilorfolk, Va'l, assigno'r to "Mnltistamp'eompany, Inc.',"Norf 'olk, Ya), a cor poratibn of Virginia 1 .This: invention relates to tracing apparatus and; among other objects, aims toprovide' an improved device of this character which may be economically. constructedand which is portable 5. and convenient to use. the drawings showing a preferred embodi ment oftheinve'ntionz Fig. 1' isa'top plan view of the improvedde'vice,

parts being broken'away;

Fig. 2 is a rear elevation thereof; r Fig. 3" is a vertical sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a vertical sectional view taken on' the line 44 of Fig. 3; and

Fig. 5 is a horizontal sectional view taken on the line 55 of Fig. 4.

Referring particularly to the drawings, the device is there shown as comprising a casing supporting a pair of spaced transparent plates, 1 such as the ground glass plate 11 and clear glass plate 12, beneath which one or more electric bulbs 13 are located, so that drawings, maps or the like placed on the top plate 11 may be traced or copied on stencil sheets, paper or any other suitable material.

The casing 10, which may be conveniently made of sheet metal, is shown as having a bottom 14, front and rear walls 15 and 16, and side walls 17 and 18. The side walls are preferably made integral with the bottom'and have their upper edges inclined, being higher at the back. The front edges of the side walls 17 and 18 and the bottom 14 are bent inwardly and upwardly respectively to provide flanges 19 to which the 36jfront wall 15 is secured, as by welding. The

upper edges of the front and side walls are provided with inwardly bent flanges 20, and the rear wall is likewise provided with a similar flange 21 to hold the glass 11 in place.

In order to support the glass plates 11 and 12, a channel member 22 is welded to each side wall near the top, the upper lateral flange 23 being spaced from the flange 20 to accommodate the glass which it supports. 'An angle member 45. 24, secured to the front wall, supports the front end of the glass and an angle member 25, extending across the casing and secured at its ends to the flanges 23, supports the rear end of the glass. The lower glass 12, which is spaced from the upper glass 11, to provide a dead air space to insulate the top glass from the heat of the bulb, is supported at its side edges on the lower lateral flanges 26 of the channels 22 and is retained in place by angle clips 27 secured to the 5.5...ohannels. The front and rear edges of the glass 12ma'y be supportedin a manner similar to-glass 11 but it is notdeerned necessary in view o'f'the fact that all of the strain is on the top glass. Iii-order thatthe glass plates may be removably plaoedin the casing, the rear wall 16 is hinged at one-side edge on hinges 28 a'ndh'eld in place by a spring latch 29 at the othe'r 'sideedge. By swinging the rear wall open, the glass plates may bslid' into or out of their places on) their respective supporting members. j

To make the bulb -13" easily replaceable; it is' mounted in a socket 30 carried by the hinge'd w'all 16, so that as the rear wall is swung open the bulb swings out of the casing. The socket is spaced from the wall, being mounted on a U-shaped bracket 31, secured by welding to the Wall, to provide room for a receptacle 32 which'is secured to the rear wall by screws 33 and connected by suitable wires 34 to the socket 30. The receptacle extends through the rear wall, being substantially flush with the outer surface thereof. A conventional electric plug (not shown) connected with a source of electricity is adapted to be inserted in the receptacle to supply current to the bulb.

In order to permit the air heated by the bulb to escape, thus permitting the ingress of cool air, a plurality of holes 35 are provided in all of the walls below the glass 12 and smaller holes 36 are provided in the walls and in the webs of the. channels below the glass 11 and above the glass 12, thereby to ventilate the space between the plates.

To provide arm rests for the operator of the device, an L-shaped shelf 37 is secured to the casing, extending outwardly from'the front wall and one side wall, the top of the shelf being flush with V the flanges 20. The shelf has a downwardly bent flange 38 along its inner edge by means of which it is welded to the casing and is strengthened by a downwardly bent flange 39 at its outer I edge. Brackets 40, welded to the shelf and to the casing, support the shelf at its ends. Herein, the shelf is shown as being at the front and at the right hand side of the casing, but may extend entirely around the casing, if desired. However, it is usually only the right arm which needs support.

As will be apparent from the drawings, the device is compact and of relatively low height, so that it may be placed on a table or desk and used conveniently. The inside of the casing is preferably coated with a white material, such as enamel or lacquer, to reflect the light from the bulb and increase its efiiciency, and eliminate spotting of the light. The top glass is made of ground glass to prevent glare.

Obviously, the present invention is not restricted to the particular embodiment thereof herein shown and described.

What I claim is:

1. A tracing device comprising, in combination, a casing closed on all sides; a source of light within the casing; a hinged door forming one of said sides; inclined guides at the top of the casing; a translucent plate at the top of the casing and slidably held in the inclined guides; the hinged door holding the translucent plate in position, when closed, and being then substantially in contact with the high edge of said plate.

2. A tracing device comprising, in combination, a casing closed on all sides; a hingeddoor forming one of said sides; inclined guides at the top of the casing; a translucent plate at the top of the casing and slidably held in the inclined guides; the hinged door holding the translucent plate in position, when closed, and being then substantially in contact with the high edge of said plate; and an electric light mounted on the inside of said hinged door.

'3. A tracing device comprising, in combination, a shallow casing having front, rear and sidewalls;

inwardly bent retaining flanges at the upper edge of each wall; means in the casing to support a pair of spaced translucent plates beneath the flanges; one of said walls being hinged to swing outwardly to permit the plates to be slid into or out of the casing; and a source of illumination within the casing.

4. A tracing device comprising, in combination, a shallow casing having front, rear and side walls; inwardly bent retaining flanges at the upper edge of each wall; channel members secured to the side walls beneath the flange and having lateral flanges; a translucent plate supported on the upper lateral flanges beneath the retaining flanges; a second translucent plate beneath the first plate and supported on the lower lateral flanges; angle members to retain the lower plate on the lower flanges; said walls having openings communicating with the space between the plate and having other openings below the lower plate; and a source of illumination within the casing.

5. A tracing device comprising, in combination, a shallow casing having front, rear and side walls; inwardly bent retaining flanges at the upper-edge of each wall; channel members secured to the side. walls beneath the flange and having lateral flanges; a translucent plate supported on the upper lateral flanges beneath the retaining flanges; a second translucent plate'below the first plate and supported on the lower lateral flanges; said ,walls having openings communicating with the space between the plate and having other openings below the lower plate; one of said walls being hinged to swing outwardly to permit removal of the plates; a socket member secured to the hinged wall; and an electric bulb mounted in the socket.- V

' WILLIAM D. MASON. 

